6m17

Structural highlights

Disease

[S6A19_HUMAN] Hartnup disease;Iminoglycinuria. The disease is caused by mutations affecting the gene represented in this entry. The disease may be caused by mutations affecting the gene represented in this entry. SLC6A19 deficiency combined with haploinsufficiency of SLC6A20 or partially inactivating mutations in SLC36A2, can be responsible for hyperglycinuria. The disease may be caused by mutations affecting the gene represented in this entry. SLC6A19 deficiency combined with haploinsufficiency of SLC6A20 or partially inactivating mutations in SLC36A2, can be responsible for iminoglycinuria. Additional polymorphisms and mutations in SLC6A18 can contribute to the IG phenotype in some families.

Function

[S6A19_HUMAN] Transporter that mediates resorption of neutral amino acids across the apical membrane of renal and intestinal epithelial cells (PubMed:18424768, PubMed:18484095, PubMed:19185582, PubMed:26240152). This uptake is sodium-dependent and chloride-independent (PubMed:19185582, PubMed:15286788). Requires CLTRN in kidney or ACE2 in intestine for cell surface expression and amino acid transporter activity (PubMed:19185582, PubMed:18424768).^{[1] [2] [3] [4] [5]} [SPIKE_SARS2] attaches the virion to the cell membrane by interacting with host receptor, initiating the infection (By similarity). Binding to human ACE2 receptor and internalization of the virus into the endosomes of the host cell induces conformational changes in the Spike glycoprotein (PubMed:32142651, PubMed:32075877, PubMed:32155444). Uses also human TMPRSS2 for priming in human lung cells which is an essential step for viral entry (PubMed:32142651). Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membranes fusion within endosomes.[HAMAP-Rule:MF_04099]^{[6] [7] [8]} mediates fusion of the virion and cellular membranes by acting as a class I viral fusion protein. Under the current model, the protein has at least three conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. During viral and target cell membrane fusion, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. The formation of this structure appears to drive apposition and subsequent fusion of viral and target cell membranes.[HAMAP-Rule:MF_04099] Acts as a viral fusion peptide which is unmasked following S2 cleavage occurring upon virus endocytosis.[HAMAP-Rule:MF_04099] [ACE2_HUMAN] Carboxypeptidase which converts angiotensin I to angiotensin 1-9, a peptide of unknown function, and angiotensin II to angiotensin 1-7, a vasodilator. Also able to hydrolyze apelin-13 and dynorphin-13 with high efficiency. May be an important regulator of heart function. In case of human coronaviruses SARS and HCoV-NL63 infections, serve as functional receptor for the spike glycoprotein of both coronaviruses.^{[9] [10] [11]}

See Also

• Angiotensin-Converting Enzyme 3D structures

References

1. ↑ Seow HF, Broer S, Broer A, Bailey CG, Potter SJ, Cavanaugh JA, Rasko JE. Hartnup disorder is caused by mutations in the gene encoding the neutral amino acid transporter SLC6A19. Nat Genet. 2004 Sep;36(9):1003-7. doi: 10.1038/ng1406. Epub 2004 Aug 1. PMID:15286788 doi:http://dx.doi.org/10.1038/ng1406
2. ↑ Kowalczuk S, Broer A, Tietze N, Vanslambrouck JM, Rasko JE, Broer S. A protein complex in the brush-border membrane explains a Hartnup disorder allele. FASEB J. 2008 Aug;22(8):2880-7. doi: 10.1096/fj.08-107300. Epub 2008 Apr 18. PMID:18424768 doi:http://dx.doi.org/10.1096/fj.08-107300
3. ↑ Azmanov DN, Kowalczuk S, Rodgers H, Auray-Blais C, Giguere R, Rasko JE, Broer S, Cavanaugh JA. Further evidence for allelic heterogeneity in Hartnup disorder. Hum Mutat. 2008 Oct;29(10):1217-21. doi: 10.1002/humu.20777. PMID:18484095 doi:http://dx.doi.org/10.1002/humu.20777
4. ↑ Camargo SM, Singer D, Makrides V, Huggel K, Pos KM, Wagner CA, Kuba K, Danilczyk U, Skovby F, Kleta R, Penninger JM, Verrey F. Tissue-specific amino acid transporter partners ACE2 and collectrin differentially interact with hartnup mutations. Gastroenterology. 2009 Mar;136(3):872-82. doi: 10.1053/j.gastro.2008.10.055. Epub, 2008 Oct 29. PMID:19185582 doi:http://dx.doi.org/10.1053/j.gastro.2008.10.055
5. ↑ Fairweather SJ, Broer A, Subramanian N, Tumer E, Cheng Q, Schmoll D, O'Mara ML, Broer S. Molecular basis for the interaction of the mammalian amino acid transporters B0AT1 and B0AT3 with their ancillary protein collectrin. J Biol Chem. 2015 Oct 2;290(40):24308-25. doi: 10.1074/jbc.M115.648519. Epub 2015, Aug 3. PMID:26240152 doi:http://dx.doi.org/10.1074/jbc.M115.648519
6. ↑ Wrapp D, Wang N, Corbett KS, Goldsmith JA, Hsieh CL, Abiona O, Graham BS, McLellan JS. Cryo-EM structure of the 2019-nCoV spike in the prefusion conformation. Science. 2020 Feb 19. pii: science.abb2507. doi: 10.1126/science.abb2507. PMID:32075877 doi:http://dx.doi.org/10.1126/science.abb2507
7. ↑ Hoffmann M, Kleine-Weber H, Schroeder S, Kruger N, Herrler T, Erichsen S, Schiergens TS, Herrler G, Wu NH, Nitsche A, Muller MA, Drosten C, Pohlmann S. SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked by a Clinically Proven Protease Inhibitor. Cell. 2020 Apr 16;181(2):271-280.e8. doi: 10.1016/j.cell.2020.02.052. Epub 2020, Mar 5. PMID:32142651 doi:http://dx.doi.org/10.1016/j.cell.2020.02.052
8. ↑ Walls AC, Park YJ, Tortorici MA, Wall A, McGuire AT, Veesler D. Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein. Cell. 2020 Mar 6. pii: S0092-8674(20)30262-2. doi: 10.1016/j.cell.2020.02.058. PMID:32155444 doi:http://dx.doi.org/10.1016/j.cell.2020.02.058
9. ↑ Donoghue M, Hsieh F, Baronas E, Godbout K, Gosselin M, Stagliano N, Donovan M, Woolf B, Robison K, Jeyaseelan R, Breitbart RE, Acton S. A novel angiotensin-converting enzyme-related carboxypeptidase (ACE2) converts angiotensin I to angiotensin 1-9. Circ Res. 2000 Sep 1;87(5):E1-9. PMID:10969042
10. ↑ Tipnis SR, Hooper NM, Hyde R, Karran E, Christie G, Turner AJ. A human homolog of angiotensin-converting enzyme. Cloning and functional expression as a captopril-insensitive carboxypeptidase. J Biol Chem. 2000 Oct 27;275(43):33238-43. PMID:10924499 doi:http://dx.doi.org/10.1074/jbc.M002615200
11. ↑ Li W, Moore MJ, Vasilieva N, Sui J, Wong SK, Berne MA, Somasundaran M, Sullivan JL, Luzuriaga K, Greenough TC, Choe H, Farzan M. Angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus. Nature. 2003 Nov 27;426(6965):450-4. PMID:14647384 doi:http://dx.doi.org/10.1038/nature02145
12. ↑ Yan R, Zhang Y, Li Y, Xia L, Guo Y, Zhou Q. Structural basis for the recognition of the SARS-CoV-2 by full-length human ACE2. Science. 2020 Mar 4. pii: science.abb2762. doi: 10.1126/science.abb2762. PMID:32132184 doi:http://dx.doi.org/10.1126/science.abb2762